Prosthetic device



g- 5, 1 E. M. BURGER EI'AL 2,605,475 PROSTHETI'C DEVICE Filed May 6, 1947 FIG.

INVENTORS EDWIN M. BURGER ATTORNEY BY ROBERT E. DE PUY Patented Aug. 5, 1952 I PROSTHETIG DEvIcE Edwin M. Burger, Akron, Ohio, and Robert E. De-

-Puy, Wilmington, Del., assignors to Wingfoot Corporation, Akron, Ohio,

Delaware a corporation of Application May 6, 1947, Serial No. 746,304

3 Claims. (c1. 3-6) The present invention relates to a prosthetic device and particularly to a prosthetic device which is to be used with a stump of a leg where the amputation is between the knee and the ankle, although its use is not limited solely to that type. For simplicity in describing the invention, reference will be made to the part that is attached to the stump as the leg portion; the part which is to go into the shoe as the foot portion, with a toe portion at the forward end of the foot portion. The part connecting the leg portion and the foot portion will be referred to as the ankle joint and it is with the ankle joint that this invention is primarily concerned.

'Oneobject of this invention is to provide a prosthetic device in which the ankle joint permitsnot only a forward and backward motion of the leg and foot portions relative to each other, but also permits a lateral movementat substantially right angles thereto. These movements, while permitted, are resisted by-a torsional stress set up in the two rubber bushings of the ankle joint.

Another objectiof this invention is to provide an ankle joint in which the forward and backward movement of the leg portion relative to the foot portion, as well as-the lateral motion thereof, is resisted by yieldable rubber means bonded or otherwise secured against slippage or movement relative to the bearing in which it is mounted. Another object of the present invention is to provide a device in which the ankle joint is'so constructed as to exclude from the operating parts thereof, any foreign matter that may tend to impair the functions thereof. Practically speakmg, the device is so constructed that evenwitho ut'the covering on the foot portion and the leg portion, dirt and foreign matter are not likely to impair the operation of the device. At least foreignmatter will not destroy the functioning, although it may temporarily tend to reduce its efficiency such as, for example, "when sufl'icient foreign'matter accumulates as to fill in any gaps between-the articulated members. However, the construction" is such' that when this foreign matter is removed, "the partswill still function as efficiently as before. r

In many devices of this type, ballbearings and 7 other bearings having -relatively" .movableparts are dan aflged very readily by foreign particles ac cumulating therein. This destroys the eflicienc y of ma ame and it will not operate as well even after the foreign matter is removed. I

Further objects of t finventioh will appear hereinafter as the description thereof proceeds, the novel features, combinations and arrangement being clearly set forth in this specification and the claims thereunto appended.

In the drawings:

Fig. 1 is a side elevation of a prosthetic device embodying'the invention; shown partly in section; Y

Fig. 2 is a front elevation view of the device I looking from the left in Fig. 1;

Fig. 3 is a perspective view showing the construction of the main frame or foot portion;

Fig; 4is an exploded view showing details of the ankle joint; and a "Fig. 5 is aperspectiveviewwith parts'broken away for the sake of clearness, illustrating'the invention in its complete form, including the outer elastic covering therefor.

The leg portion I comprises a lightweight framework, preferably made of magnesium and cored out' to elfect the necessary lightness While retaining the desired strength. This leg portion has two downwardly extending ears 2 at opposite sides thereof, as viewed in Fig. 2, for a purpose which will be described presently. The foot portion3 is a lightweight framework more clearly illustrated in Fig.- 3 and also made of magnesium and cored out so as to effect a minimum amount of weight for this portion. Inorder to provide a toe portion of the requisite flexibility, the forward end of the foot portion may be and preferably is provided with a fiat spring 4 having an offset portion 5 secured'by rivets 6 other suitable means to the foot portion 3. The toe portion 4 and the foot portion 3 are eventually covered with a layer of sponge rubber or, plastic material which is preferably somewhat deformable and resilient and molded into the shapeof a foot, the whole to be encased in a flexible stocking orv the like. I

The parts I and 3 are connectedby an ankle joint shown in Figs. 1, land 4. This joint, as best illustrated in- Fig. 4, comprises two metal sleeves Tand B integrally joined to each other at right angles. Each sleeve is provided withinner concentrically arranged sleeves 9 and l 0, respectively, and arrangedbetween the sleeves land 9,

andv the sleeves 3 and Ill are bodies of rubber H and]; which are held against slippage with re spect tof'thei r respective sleeves. This'may be e by h h y; c m r ssin tharubber between i thefsleeve's, cementing the a rubber tothe sleeves but, preferably, by vulcanizing the; rubber into intimate adhesion witli the contactingimetal sullfaces infa manner wellunderstood injthefart. "Primarily, the sleeve 9 is adapted to'be conportion;

i Q 33! seoffthe"rubberYtorsmmbusm rewer e heie i i 'iibe s er a- .1a,

nected to the leg portion l' in such a way as to be rigidly connected thereto and move therewith. Similarly, the sleeve 1!! is adapted to be connected to and move with the foot portion 3. These sleeves are so connected to their respective parts that they cannotrotate with respect thereto, nor shift longitudinally thereof. In order to prevent the rotation of the sleeve 9 with respect to the leg portion I, we provide notches l3 in the ends of the sleeve 9 into which the projections I4 on the 110 ears 2 project. The sleeve 9 is internally threaded,

at both ends as at l5 and the hollow'locking screws I6 are threaded into the sleeve 9 :rmm:

either side to draw the ears 2 inwardly to cause the projections [4 to firmly seat'thems'elves in the notches l3. As shown in Figs. 1 and 5 particularly, it will be noted that the screws I6 have hex agonal openings I! in the ends thereof for the reception of a similarly shaped tool to be inserted therein for tightening up the screws it.

,The sleeve!!! is lockedin a similar, although not identical, manner to that vdescribed.""with respect to sleeve 9. This sleeve'is provided. with notches only at one end thereofas'at'la and'these are adapted to interlock with projections lfi on the portion 2001 the frame 3. .Ap'in 2 lithreaded at22 and 23 is inserted through the inner sleeve as best illustrated in Fig. 1 with the unthreaded portions '24 and 25 bearing in portions of the framework to carry the load. A nut 26 threaded *locksthe sleeve H) with respect to the foot :por-

tion. a

as to give varying degrees of resistance and rate to the articulation of the leg and foot portions. A different type of rubber can be used for one bushing than for the other in order, for example, to give greater stifiness or a different rate to one torsion unit. By having a selection of torsion units of varyingdegrees "or stiffness or in various sizes, it is possible, without'changing the other parts of the structure, to provide the prosthetic device with an ankle joint best suited tofltheindividual requirements of the amputee. The" action of the toe portion can be' regulated 1 byFch-angingthe stiffness of the spring 4.

The sleeves 9 and H! can beprovided with a series' oi notches sci-that thesleevesmay be mounted in selected angulari'positions if desired.

The forward jmotionof the leg-portion relative to'the foot portion Is-limited by a stop which comprises a threaded member-:28,threadedinto the-foot portion and carryinga rubber pad 29 which engages the flat surface301on-the-leg The threaded portion "28 of the stop permits vertical adjustment of the rubber pad 29 to, vary the amount of permitted movement of the leg portion re1ative to the foot portionin a: forward direction. A spring member 31 held plaeeby a screw 32 engages the -threadsr28 to permit locking the stop in its-adjusted position. -An,v means can be used for this purpose. Fig -o shows the completed prosthetic-device withpo'rtions thereof laid open to bettergsho w the-completed. device-in its, final form... The

tioniin any suitablemanner. as by a screw 3 53 passing through the plastic? portion si .and a suitable opening inthe frame ofv the portion,

This shinportion is usually provided at its upper: endqwith aso'cket' forlth'e rece ation. of the stump of theleg. Howeirengincase er anljanipiitation otherjtlianbelow the knee, it'fis possible to coin-. b eit Sh tt nw i suit b ans-fine likefiwithoutaffect,, t e ot? ort o 35 p at n ,of

gree, orrlexibiury or .thiahgle jointican' be. v ried knee oints .The'zlateral' rocking movement of the joint is 'limited'bytheengagement of the ears 2 with the arcuate portions 31 on the frame 3. Thus, if therubber should fail for any reason or if the inner sleeve loses its locking engagement with the-frame, the wearer will not be completely deprived of lateral support. Similarly, the rear- Wardirocking of the leg portion relative to the foot portion islimited by the engagement of'the opposed surfaces 38 and 39'.

g It will be understood, however, that various changes may bemade in the particular arrangement, construction and combinationswithout'departingfrom the'spirit oftheinvention or the scopeof the-appended claims and, therefore, the invention is not limited. except as maybe hereinaiter set. forth in the claims hereunto appended.

Having thus fully described the invention,

what is claimed anddesired' toss-cure by Letters Patent-of. the United States is? 1. A prosthetic; device oi "the class described adapted to provide an .artificial'ankle joint capable 01 restrained and yieldable concurrent romy movement between foot and leg members about transversely, disposed faxes shiftable in re: sponse to applied pressure, 7 said device comprise ing the combination with foot and leg-members. of apair of unitary-superposedsubstantially cylindrical membersfdisposed with their axes substantially at. right angles to each other and in :differenthorizontally disposed planes, apair of similarly disposed separate sleeves each ar, ranged within one -o-fthe cylindricai ,inembers in spaced relation thereto, a rubber-torsion bush i-ng {secured in each cylindrical anemberabout and; in cooperative engagementwith the sleeve disposed therein, means for holding the sleeve in the upper cylindrical member from rotary movement relative to the leg-member, and means 2. A prosthetic device.o f, the class described adapted-to provide an artificial ankle jointcap 7 ole of restrained andyieldable concurrent .rot'a r movement between foot. and leg ;members about transversely disposed axes shiftable. in response 7 toa ppl-ied pressura said device comprising the combination with appen leg memberspf a pair o f --.unitary superposed substantially cylin; drical members disposed witlrtheir-axes substa tiallyeatright angles-to eachyother and-ind ierenthorizontally disposed -;p-lanes, a; pair oi similarlydisposed separate sleeves, each of z-saidsleeves being arranged respectively about.one .-of.

' seouredineach y said axesandwvithinand inlspaced relation -to the, cylindrical rnember, which is v coaxial with 'e e zi ei a /e l bber tw e u i lindrieal member ;about:and'i n h the sleevedis er i cooperative. engagement,

de a -.-:m m r item;

sleeve in one;cy.l 1 n-, i I .meteiee re ei i to the leg member, and means for holding the sleeve in the other cylindrical member from rotary movement relative to the foot member.

3. A prosthetic device of the class described adapted to provide an artificial ankle joint capable of restrained and yieldable concurrent rotary movement between foot and leg members about transversely disposed axes shiftable in response to applied pressure, said device comprising a pair of unitary superposed substantially cylindrical members disposed with their axes substantially at right angles to each other and in difierent horizontally disposed planes, a pair of similarly disposed separate sleeves each arranged within one of the cylindrical members in spaced relation thereto, a rubber torsion bushing secured in each cylindircal member about and in cooperative engagement with the sleeve disposed therein, the sleeve disposed in the upper of said cylindrical members being interiorly threaded at each end thereof and having circumferentially spaced notches in the ends thereof, means for securing the latter sleeve to the leg member comprising a pair of downwardly extending ears spaced laterally to embrace the ends of said latter sleeve, circumferentially spaced projections on opposing faces of said ears registering with and lodged in said notches for holding said latter sleeve from rotary movement relative to said ears, bolts extending through said ears in threaded engagement with the interior threads at the ends of said latter sleeve for securing this sleeve and said ears together in fixed relation, a foot member, means for securing the other sleeve to the foot member comprising transversely disposed walls carried by and spaced longitudinally of the foot member to define a recess receiving and. embracing the ends of said other sleeve and the lower cylindrical member, said walls having bores aligned substantially coaxially with the lower cylindrical member and said other sleeve to provide radial bearings for a tightening pin, the forwardly disposed end 6 of said other sleeve being interiorly threaded, a tightening pin fitting said bores and extending through said other sleeve and having threaded engagement with said interiorly threaded forwardly disposed end thereof, the rearwardly disposed end of said other sleeve having circumferentially spaced notches, circumferentially spaced projections on the forwardly facing side of the rearmost of said walls, said projections registering with and being lodged in said notches for holding said other sleeve from rotary movement relative to the foot member, said tightening pin having a threaded portion extending rearwardly of said rearmost wall, and a knot on the last mentioned threaded portion for drawing said tightening pin and said other sleeve against said rearmost wall.

EDWIN M. BURGER. ROBERT E. DE PUY.

REFERENCES CITED The following references are of record in the idle of this patent:

UNITED STATES PATENTS Number Name Date 1,224,368 Feltes May 1, 1917 1,294,632 Dickson Feb. 18, 1919 1,911,440 Desoutter May 30, 1933 2,019,052 Lord Oct. 29, 1935 2,252,206 Rice Aug. 12, 1941 FOREIGN PATENTS Number Country Date 358,818 Germany Sept. 16, 1922 518,258 Great Britain Feb. 21, 1940 OTHER REFERENCES Report on European Observations, page 37, lines 16-25. (A copy was received in Div. 55, Feb. 12, 1947, by the Commission on Amputations and Protheses.) 

